To find out what version of .Net is installed on the target system, follow the steps below

1. Open a command prompt go to start -> run -> and type cmd
2. At the command prompt type reg query "hklm\software\microsoft\net framework setup\ndp" (the double quotes are need since there are spaces in the path)
3. You then will see a list of .Net versions installed on your system in the command prompt window (see below).

On the queried system you should see that .NET 1.1.X, 2.0.X, 3.0, and 3.5 are installed